1. Field of the Invention
The present invention generally relates to semiconductor devices, and more specifically to improving ETSOI MOSFETS.
2. Description of Related Art
Metal Oxide Semiconductor Field Effect Transistors (MOSFETS) are commonly used today in almost all electronic circuit applications. An emerging technology in the field of semiconductor-on-insulator (SOI) FET devices is the extremely thin semiconductor-on-insulator (ETSOI) MOSFET. Such a device shows excellent short channel control, which is desirable. With the trend toward continued scaling of MOSFET devices, ETSOI is a promising candidate for next generation technology.
There are, however, several manufacturing issues that can limit yield. Specifically, as the STI divot erodes as a function of the HF based cleaning and other process steps during manufacturing, the back gate or substrate wafer is exposed, leaving it susceptible to shorting due to s/d epitaxy and unwanted metal gate connections, among other processes.